(1) Field of the Invention
The present invention relates to an artificial stone molded body and a process for the fabrication thereof. More specifically, the present invention relates to an artificial stone molded body having a moderated internal stress and excellent quality and appearance, and a process for fabricating this molded body in a short time by hardening an inorganic filler by a resin binder.
(2) Description of the Prior Art
Unsaturated polyesters, epoxy resins and acrylic resins have heretofore been used as the resin binder for the fabrication of artificial stone molded bodies, and recently, acrylic resins are widely used because acrylic resins are excellent in the transparency and weatherability. However, acrylic resins are defective in that the abrasion resistance and weatherability are poor. As the means for overcoming this defect, we proposed use of diethylene glycol bisallyl carbonate as the binder and an artificial stone molded body according to this proposal has been marketed (see Japanese Unexamined Patent Publication No. 61-111953).
The artificial stone molded body according to the above-mentioned proposal has a highest quality as the material, but this technique is defective in that since the polymerization speed is very slow at the molding step, a long time (about 15 hours) is required for completion of the molding. Moreover, since the monomer already has a substantially complete three-dimensional crosslinked structure at the initial stage and is in the state of a gel, hardening is completed in the state where the internal stress is retained. Accordingly, in order to obtain a good molded body, a mold should be carefully selected and a highly skilled technique is required.